Sir David Jason is under 24-hour protection after a "credible threat" was made against him.
The "Only Fools and Horses" actor is being heavily guarded on and off the set of BBC's "Still Open All Hours" after he was targeted by a "rogue nutter".
A source told The Sun: "Production and security have been told there has been talk of a real threat. No one is taking any chances.
"Security is extra tight compared to previous years and he has two suited guards who follow him everywhere.
"They even follow his car when he leaves the set.
"The road they film on has been barriered off halfway along and sometimes even blocked with a van."
When asked about the threat to the 77-year-old actor, a BBC spokesperson said: "We wouldn't comment on security matters."
Meanwhile, although he's achieved huge success in the UK, Sir David recently insisted he never wanted to spread his wings and attempt to crack the US - despite having offers - because he's too busy.
He explained: "Despite offers I have never felt the urge to try to make it in Hollywood. There are too many ¬interesting parts for me to play here."
With offers still flooding in, David is adamant he has no plans to retire any time soon.
He added: "I have been so fortunate. I always say, it is not the arrival, it is the journey. And there is still more to the journey left hopefully. I will continue to entertain the great British public. Because that is what I love doing."